This invention relates to a knitting-machine needle comprising a hook portion, a shank portion, and a butt portion, the shank portion having a straight, tapering front section contiguous with the hook portion and a rear section of uniform width contiguous with the butt portion.
Knitting-machine needles of this kind are used particularly in circular knitting machines intended for manufacturing stockings, for example, and working continuously. The needles are mounted in grooves of a needle bed, and control means impart to them a programmed forward-and-backward movement, each needle being moved in turn during the rotation of the carriage.
Needles of this kind must meet contradictory requirements in the sense that, while their dimensions should be as fine as possible, they must nevertheless possess good resistance to the considerable stresses to which they are subjected. Moreover, the main dimensions of the needles, especially their overall length, their thickness, and the distance by which the shank projects from the needle bed in its forwardmost position, are governed by the structure of the knitted fabric and are, consequently, obligatory.
Thus the contradictory requirements mentioned above, plus the fact that efforts are constantly being made to increase the speed at which the machines operate, oblige the manufacturers of needles to seek new designs which enable users of these highspeed machines to get the most out of them. In order to make the needle lighter, especially the rearward portion of it, while still ensuring satisfactory guidance of the butt in the groove in which the needle is engaged, the tendency has been to reduce the width of the butt to a certain extent and to provide needles having a trapezoidal zone at the base of the butt. However, this improvement has not remedied one drawback which appears in the machines operating at the highest speeds to be found at the present time. This drawback is the vibration of the hook after the forward thrust of the needle and after its rapid return backwards, which vibration causes breakage of the hook after some time.